<div id="tree"><ul></ul></div>
<pre id="code"></pre>
<div id="info" hidden>
  <header>
    <span id="i_symbol"></span>
    <span id="i_kind"></span>
  </header>
  <section>
    <div id="i_rules"></div>
    <div id="i_alternatives"></div>
  </section>
  <section>
    <div id="i_ancestors"></div>
  </section>
</div>
